Materials Literature
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The adsorptive potential of multiwalled carbon nanotubes (MWNTs) for solid-phase extraction of bisphenol A, 4-n-nonylphenol, and 4-tert-octylphenol was investigated for the first time. The three analytes are quantitatively adsorbed on a MWNTs-packed cartridge, then the analytes retained on the cartridge are quantitati…
A rapid immunoassay capable of detecting analyte within complex biological media without any sample preparation is described. This was accomplished using gold nanoshells, layered dielectric-metal nanoparticles whose optical resonance is a function of the relative size of its constituent layers. Aggregation of antibody…
A general framework for the interpretation of infrared and Raman spectra of amorphous carbon nitrides is presented. In the first part of this paper we examine the infrared spectra. The peaks around 1350 and 1550 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ found in the infrared spectrum of amorphous carbon nitride or hy…
Abstract We have recently developed a simple and versatile route to the large‐scale synthesis of metal nanostructures with well‐defined hollow interiors. The key step of this process involves a replacement reaction between the surface of a nanoscale template and the solution of an appropriate salt precursor. The capab…
We have studied two specific models of frustrated and disordered coupled Kuramoto oscillators, all driven with the same natural frequency, in the presence of random external pinning fields. Our models are structurally similar, but differ in their degree of bond frustration and in their finite size ground state propert…
There is economic incentive to operate the ethylbenzene dehydrogenation reaction at low steam/ethylbenzene ratios. To develop catalysts capable of performing under these conditions, it is necessary to understand the mechanism whereby the concomitant activity loss occurs. A potentially important mechanism is the reduct…
We have found a secreted phospholipase A(2) (PLA(2), EC 3.1.1.4) from Streptomyces violaceoruber A-2688, which is the first PLA(2) identified in prokaryote, and determined its tertiary structure by NMR and X-ray analyses. In this study, we collected the X-ray diffraction data of the bacterial PLA(2) at room temperatur…
A possible role that might have been played by ordered clusters at interfaces for the generation of homochiral oligopeptides under prebiotic conditions has been probed by a catalyzed polymerization of amphiphilic activated alpha-amino acids, in racemic and chiral non-racemic forms, which had self-assembled into two-di…
Δ 4,4‘ -Dicyclopenta[2,1- b:3,4- b ‘]dithiophene has been prepared from cyclopenta[2,1- b:3,4- b ‘]bithiophen-4-one and its electrochemical and spectroscopic properties have been characterized. Its low HOMO−LUMO gap and facile electrochemical polymerization make it an attractive building block for low band gap conduct…
We examine the fluid-solid transition for a hard-disk system. By counting the near neighbors in the average configurations of a grand-canonical Monte Carlo simulation, this enables us to relate the thermodynamic transition with the rigidity theory, since we find that the coordination number in the fluid-solid transiti…
Microscopic rate constants for Tb( 5 D 3 ) cross relaxation have been determined as a function of temperature in symmetrical Tb 3+ −Tb 3+ pairs in CsCdBr 3, CsMgBr 3 and CsMgCl 3 . The temperature dependence and maximum efficiency of cross relaxation is very different in the three hosts, despite the fact that the ener…
The phase transition from the isotropic (I) to nematic (N) liquid crystalline suspension of F-actin of average length ł> or =3 microm was studied by local measurements of optical birefringence and protein concentration. Both parameters were detected to be continuous in the transition region, suggesting that the I-N tr…
The effects of molecular architecture on the fracture properties of semicrystalline polymers were probed at diblock copolymer-reinforced interfaces between polystyrene (PS) and polyethylene (PE). The PE used for this study was a model ethylene−butene copolymer which was chosen for its compatibility with hydrogenated 1…
The segmental tris-tridentate ligand L7 reacts with stoichiometric quantities of Ln(III) (Ln=La-Lu) in acetonitrile to give the complexes [Ln(2)(L7)(3)](6+) and [Ln(3)(L7)(3)](9+). Formation constants point to negligible size-discriminating effects along the lanthanide series, but Scatchard plots suggest that the self…
A series of perovskites with the compositions NaTi x Nb 1 - x O 3 - 0.5 x (0 ≤ x ≤ 0.2) has been synthesized for the first time using the sol−gel method. Combined Rietveld analysis of powder neutron and X-ray diffraction data reveals that these phases adopt the structure of the end-member perovskite NaNbO 3 with the s…
A new family of three-dimensional cubic-like [M(dca)3]− networks (dca = dicyanamide) templated by appropriate cations has been constructed and structurally characterized by X-ray crystallography.
Well-defined arrays of porphyrins attached to a rigid polyisocyanide backbone have been synthesized and their physical and optical properties studied. The helical polymers are rigidified by an inter-side chain hydrogen-bonded network and have an average mass of 1.1 x 10(6) Daltons and a polydispersity index of 1.3. Ea…
The layer-by-layer deposition method to prepare multilayers of polyelectrolytes of alternating charge has been followed in situ by means of optical reflectometry. It has been shown previously that in solutions containing both weak polyelectrolytes and appropriate salt the buildup of multilayers is modified and becomes…
Some recent publications on ferromagnetic resonance in amorphous wires mention presumably new kind of anisotropy, called there circumferential anisotropy, as an explanation of various spectral features. In this paper we argue that there is no special reason to speak of the new kind of anisotropy, since the observed sp…
Using density-functional theory we assess the stability of bulk and surface oxides of the late 4d transition metals in a ``constrained equilibrium'' with a gas phase formed of O2 and CO. While the stability range of the most stable bulk oxide extends for ruthenium well into gas phase conditions representative of techn…